Embodiments of the present invention are directed to position sensing and movement between components, and more particularly to the alignment and/or docking between these components.
The ability to determine a relative relationship between distinct components has considerable uses. For example, offset sensing between two plates is of value for automatic active docking of self-configurable robot systems. One such system is known as a PolyBot (a robotic system of Xerox Corporation), which uses repeated modules with identical docking mechanisms or interface plates.
In the past, expensive optics and cameras have been used for docking of kinematic chains and robotic arms. One such system is a virtual reality (VR) hardware system, which uses six degree of freedom trackers. Such systems include linkage-based concepts, electro-magnetic fuel based systems, ultrasonic rangings, and inertial tracking methods, among others. The ultrasonic and inertial tracking methods have not been extended to six degree of freedom (DOF) in a robust fashion. The vision based methods tend to be computationally intensive and expensive. The electromagnetic based methods are the most popular for VR. However, they do not work well for self-configurable systems since they are prone to interference of metallic objects and are expensive to implement.
Other non-light based positional methods include eddy-current sensing, hall effect sensors or capacitance based methods. Drawbacks of these methods are the intimate presence of electric motors, which may cause too much noise to make the sensing feasible.